1. Field of the Invention
The present invention relates to an image transfer recording apparatus having a rotating drum around which an image-receiving sheet and a donor sheet having a donor layer are to be wound, and a light source for irradiating the donor sheet with a light beam based on certain image information in order that donor ink in the donor layer can be transferred to an image-receiving layer of the image-receiving sheet. Donor sheets are also called ink-films, donor films or the like, image-receiving sheets are also called image-receiving films, receivers or the like, and donor layers are also called ink-layers.
2. Description of the Related Art
In the field of printing, prior to mass printing at a high speed, to save time and money, a trial printing for proofreading is generally carried out.
There are several types of printers for such a proofreading. Among those printers, a transfer-type image recording apparatus is known in which it enables a colorful image formation although it is relatively simple and small in scale.
The above-type apparatus utilizes image-receiving sheets and donor sheets. In operation, an image-receiving sheet is wound around an exposure drum, and then, a donor sheet is wound therearound.
Thereafter, by laser-exposure, donor ink in the donor sheet is transferred onto the image-receiving sheet to thereby form an image thereon.
To complete a color image formation, the same sequence of processing is repeated with respect to a plurality of colors of donor sheets.
The key to ensuring a reliable ink transfer process is to achieve good adhesion between an image-receiving sheet and a donor sheet. If adhesion is not good due to, for example, air bubbles generated therebetween, the transfer process will be unsuccessful irrespective of how excellent the exposure process may be.
In light of the above-mentioned fact, a primary object of the present invention is to provide an image transfer recording apparatus that enables an excellent adhesion between an image-receiving sheet and a donor sheet.
To achieve the object mentioned above, according to an aspect of the present invention, there is provided an image recording apparatus in which ink transfer from a donor sheet to an image-receiving sheet is carried out, the donor sheet having a larger size than the image-receiving sheet, and the image recording apparatus including: a rotating drum around which the image-receiving sheet and the donor sheet can be laminatingly wound in this order; a squeeze roller disposed to releasably press the donor sheet and the image-receiving sheet against the drum, a middle portion in an axial direction of the squeeze roller having a substantially constant radius and a smaller diameter portion at at least one end thereof in the axial direction having a radius smaller than the radius of the middle portion; wherein the drum includes a first protruding mound portion which, when the image-receiving sheet and the donor sheet are wound around the drum, is apart from an edge of the image-receiving sheet substantially by a predetermined distance and is in surface-contact with the donor sheet, and when the squeeze roller is pressing the donor sheet and the image-receiving sheet against the drum, a boundary portion between the smaller diameter portion and the middle portion of the squeeze roller is disposed at a side of the first mound portion at which the image-receiving sheet is disposed.
The foregoing and other objects, features and advantages of the present invention will be apparent from the following description of a preferred embodiment of the invention, as illustrated in the accompanying drawings.